Files
irtt-rs/crates/irtt-stats/tests/common/mod.rs
T
Nils Andreas Svee db9bd515bb refactor(stats): retain exact finite timing samples
`SampleMode::Exact` retained exact samples for eight of the eleven public
timing metrics. Send call, timer error, and server processing always built
their `TimeMetric` with retention disabled, so a finite run reported no
median for them even though they are the same public `TimeStats` type and
appear in the same summary table with a Median column.

Derive one `retain_exact` decision from the sample mode in `CoreStats::new`
and apply it to every timing metric, so exact mode means the same thing for
all of them. Running-only mode is unchanged and still retains none of them.

The retention estimator counted eight exact sample streams per measurable
reply. Rename it to the eleven exact samples an ordinary successful probe
can retain and document the wider optional-measurement upper bound, which
raises the finite estimate on this target from 668 to 764 bytes per probe.
A test counts the metrics a fully measured probe actually retains and
compares it against that constant, so retention and its estimate cannot
drift apart unnoticed.

No new median-capability type was needed: `TimeStats::median_ns` already
distinguishes a retained median from an absent one, and an optional
measurement the server never supplied still produces no samples at all.
2026-08-15 10:41:17 +07:00

188 lines
5.5 KiB
Rust

use std::time::{Duration, Instant, UNIX_EPOCH};
use irtt_client::{
ClientEvent, ClientTimestamp, OneWayDelaySample, PacketMeta, ReceivedStatsSample, RttSample,
ServerTiming, SignedDuration,
};
pub fn ts(ms: u64) -> ClientTimestamp {
ClientTimestamp {
mono: Instant::now() + Duration::from_millis(ms),
wall: UNIX_EPOCH + Duration::from_millis(ms),
}
}
pub fn adjusted_rtt(raw_ms: u64, adjusted_ms: i128) -> RttSample {
let adjusted = SignedDuration::from_nanos(adjusted_ms * 1_000_000);
RttSample {
raw: Duration::from_millis(raw_ms),
adjusted: Some(adjusted),
effective: adjusted,
}
}
pub fn unadjusted_rtt(raw_ms: u64) -> RttSample {
let raw = Duration::from_millis(raw_ms);
RttSample {
raw,
adjusted: None,
effective: SignedDuration::from_duration(raw),
}
}
pub fn sent(seq: u32, sent_at: ClientTimestamp) -> ClientEvent {
ClientEvent::EchoSent {
seq,
remote: "127.0.0.1:2112".parse().unwrap(),
scheduled_at: sent_at.mono,
sent_at,
bytes: 32,
send_call: Duration::from_micros(10),
timer_error: Duration::from_micros(2),
}
}
pub fn adjusted_reply(seq: u32, raw_ms: u64, adjusted_ms: i128) -> ClientEvent {
reply_with_rtt(seq, raw_ms, adjusted_rtt(raw_ms, adjusted_ms))
}
pub fn unadjusted_reply(seq: u32, raw_ms: u64) -> ClientEvent {
reply_with_rtt(seq, raw_ms, unadjusted_rtt(raw_ms))
}
fn reply_with_rtt(seq: u32, raw_ms: u64, rtt: RttSample) -> ClientEvent {
let sent_at = ts(seq as u64 * 10);
let received_at = ClientTimestamp {
mono: sent_at.mono + Duration::from_millis(raw_ms),
wall: sent_at.wall + Duration::from_millis(raw_ms),
};
ClientEvent::EchoReply {
seq,
remote: "127.0.0.1:2112".parse().unwrap(),
sent_at,
received_at,
rtt,
server_timing: Some(ServerTiming {
receive_wall_ns: Some(unix_time_ns_after_epoch(sent_at.wall) as i64 + 1_000_000),
receive_mono_ns: Some(seq as i64 * 10_000_000 + 1_000_000),
send_wall_ns: Some(unix_time_ns_after_epoch(sent_at.wall) as i64 + 2_000_000),
send_mono_ns: Some(seq as i64 * 10_000_000 + 2_000_000),
midpoint_wall_ns: None,
midpoint_mono_ns: None,
processing: Some(Duration::from_millis(1)),
}),
one_way: Some(OneWayDelaySample {
client_to_server: Some(SignedDuration::from_nanos(1_000_000)),
server_to_client: Some(SignedDuration::from_nanos(2_000_000)),
}),
received_stats: Some(ReceivedStatsSample {
count: Some(seq + 1),
window: Some(0xff),
}),
bytes: 64,
packet_meta: PacketMeta::default(),
}
}
/// Builds a normal reply carrying exactly the supplied server received stats.
pub fn reply_with_received_stats(
seq: u32,
raw_ms: u64,
count: Option<u32>,
window: Option<u64>,
) -> ClientEvent {
let mut event = unadjusted_reply(seq, raw_ms);
let ClientEvent::EchoReply { received_stats, .. } = &mut event else {
unreachable!();
};
*received_stats =
(count.is_some() || window.is_some()).then_some(ReceivedStatsSample { count, window });
event
}
/// Builds a send event with the supplied send-call duration and timer error.
pub fn sent_with_timings(
seq: u32,
sent_at: ClientTimestamp,
send_call_us: u64,
timer_error_us: u64,
) -> ClientEvent {
let mut event = sent(seq, sent_at);
let ClientEvent::EchoSent {
send_call,
timer_error,
..
} = &mut event
else {
unreachable!();
};
*send_call = Duration::from_micros(send_call_us);
*timer_error = Duration::from_micros(timer_error_us);
event
}
/// Builds a normal reply reporting exactly the supplied server processing time.
pub fn reply_with_processing(seq: u32, raw_ms: u64, processing_ms: u64) -> ClientEvent {
let mut event = unadjusted_reply(seq, raw_ms);
let ClientEvent::EchoReply { server_timing, .. } = &mut event else {
unreachable!();
};
if let Some(timing) = server_timing.as_mut() {
timing.processing = Some(Duration::from_millis(processing_ms));
}
event
}
/// Builds a normal reply from a session that supplied no server timestamps, so
/// no server processing measurement exists.
pub fn reply_without_server_timing(seq: u32, raw_ms: u64) -> ClientEvent {
let mut event = unadjusted_reply(seq, raw_ms);
let ClientEvent::EchoReply { server_timing, .. } = &mut event else {
unreachable!();
};
*server_timing = None;
event
}
pub fn unadjusted_late_reply(seq: u32, raw_ms: u64) -> ClientEvent {
late_reply_from(unadjusted_reply(seq, raw_ms))
}
fn late_reply_from(reply: ClientEvent) -> ClientEvent {
let ClientEvent::EchoReply {
seq,
remote,
sent_at,
received_at,
rtt,
server_timing,
one_way,
received_stats,
bytes,
packet_meta,
..
} = reply
else {
unreachable!();
};
ClientEvent::LateReply {
seq,
highest_seen: seq + 1,
remote,
sent_at: Some(sent_at),
received_at,
rtt: Some(rtt),
server_timing,
one_way,
received_stats,
bytes,
packet_meta,
}
}
fn unix_time_ns_after_epoch(time: std::time::SystemTime) -> i128 {
time.duration_since(UNIX_EPOCH)
.map(|duration| duration.as_nanos() as i128)
.unwrap()
}